scholarly journals Molecular Diversity and Pathogenicity of Ralstonia solanacearum Species Complex Associated With Bacterial Wilt of Potato in Rwanda

Plant Disease ◽  
2020 ◽  
pp. PDIS-04-20-0851
Author(s):  
Kalpana Sharma ◽  
Jan Kreuze ◽  
Abdulwahab Abdurahman ◽  
Monica Parker ◽  
Anastase Nduwayezu ◽  
...  
Keyword(s):  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Species Complex ◽  
Molecular Diversity ◽  
Diversity Index ◽  
Repeat Sequence ◽  
Potato Plants ◽  
Commercial Potato ◽  
History Of ◽  
Open Access Article

Bacterial wilt (BW), caused by Ralstonia solanacearum species complex (RSSC), leads to substantial potato yield losses in Rwanda. Studies were conducted to (i) determine the molecular diversity of RSSC strains associated with BW of potato, (ii) generate an RSSC distribution map for epidemiological inferences, and (iii) test the pathogenicity of predominant RSSC phylotypes on six commercial potato cultivars. In surveys conducted in 2018 and 2019, tubers from wilting potato plants were collected for pathogen isolation. DNA was extracted from 95 presumptive RSSC strain colonies. The pathogen was phylotyped by multiplex PCR and typed at sequevar level. Phylotype II sequevar 1 strains were then haplotyped using multilocus tandem repeat sequence typing (TRST) schemes. Pathogenicity of one phylotype II strain and two phylotype III strains were tested on cultivars Kinigi, Kirundo, Victoria, Kazeneza, Twihaze, and Cruza. Two RSSC phylotypes were identified, phylotype II (95.79%, n = 91) and phylotype III (4.21%, n = 4). This is the first report of phylotype III strains from Rwanda. Phylotype II strains were identified as sequevar 1 and distributed across potato growing regions in the country. The TRST scheme identified 14 TRST haplotypes within the phylotype II sequevar 1 strains with moderate diversity index (HGDI = 0.55). Mapping of TRST haplotypes revealed that a single TRST ‘8-5-12-7-5’ haplotype plays an important epidemiological role in BW of potato in Rwanda. None of the cultivars had complete resistance to the tested phylotypes; the level of susceptibility varied among cultivars. Cultivar Cruza, which is less susceptible to phylotype II and III strains, is recommended when planting potatoes in the fields with history of BW. [Formula: see text] Copyright © 2020 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

scholarly journals Molecular Epidemiology of Ralstonia solanacearum Species Complex Strains Causing Bacterial Wilt of Potato in Uganda

2019 ◽  
Vol 109 (11) ◽  
pp. 1922-1931 ◽  
Author(s):  
Abdulwahab Abdurahman ◽  
Monica L. Parker ◽  
Jan Kreuze ◽  
John G. Elphinstone ◽  
Paul C. Struik ◽  
...  
Keyword(s):  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Species Complex ◽  
Nationwide Survey ◽  
Potato Production ◽  
Repeat Sequence ◽  
Latently Infected ◽  
Pure Cultures ◽  
Diversity Studies ◽  
Phylotype I

Bacterial wilt (BW) caused by the Ralstonia solanacearum species complex (RSSC) is a serious threat to potato production in Uganda. However, little is known about the extent of the disease and the type of the pathogen strains involved. A nationwide survey was conducted to study BW prevalence and incidence in potato, and potato tuber and stem samples of potential alternative hosts were collected for pathogen isolation. DNA was extracted from pure cultures for genetic diversity studies. The pathogen was phylotyped by multiplex PCR; then, a subset of isolates was typed at sequevar level. Isolates of the same sequevar were then haplotyped using multilocus tandem repeat sequence typing (TRST) schemes. BW prevalence and incidence in potato farms were 81.4 and 1.7%, respectively. Three RSSC phylotypes were identified, with the majority of the strains belonging to Phylotype II (80%) followed by Phylotype I (18.5%) and III (1.5%). Phylotype I strains belonged to Sequevar 31, and Phylotype II strains belonged to Sequevar 1. Potato-associated Phylotype II Sequevar 1 strains were more diverse (27 TRST haplotypes) than nonpotato Phylotype I (5 TRST haplotypes). Mapping of TRST haplotypes revealed that three TRST haplotypes of Phylotype II Sequevar 1 strains play an important epidemiological role in BW of potato in Uganda being disseminated via latently infected seed. [Formula: see text] Copyright © 2019 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

scholarly journals Genetic Diversity and Aggressiveness of Ralstonia solanacearum Strains Causing Bacterial Wilt of Potato in Uruguay

Plant Disease ◽  
2011 ◽  
Vol 95 (10) ◽  
pp. 1292-1301 ◽  
Author(s):  
M. I. Siri ◽  
A. Sanabria ◽  
M. J. Pianzzola
Keyword(s):  
Genetic Diversity ◽  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Potato Tubers ◽  
Bacterial Strains ◽  
Potato Plants ◽  
Polymerase Chain ◽  
First Time ◽  
Different Levels

Bacterial wilt, caused by Ralstonia solanacearum, is a major disease affecting potato (Solanum tuberosum) production worldwide. Although local reports suggest that the disease is widespread in Uruguay, characterization of prevalent R. solanacearum strains in that country has not been done. In all, 28 strains of R. solanacearum isolated from major potato-growing areas in Uruguay were evaluated, including 26 strains isolated from potato tubers and 2 from soil samples. All strains belonged to phylotype IIB, sequevar 1 (race 3, biovar 2). Genetic diversity of strains was assessed by repetitive-sequence polymerase chain reaction, which showed that the Uruguayan strains constituted a homogeneous group. In contrast, inoculation of the strains on tomato and potato plants showed, for the first time, different levels of aggressiveness among R. solanacearum strains belonging to phylotype IIB, sequevar 1. Aggressiveness assays were also performed on accessions of S. commersonii, a wild species native to Uruguay that is a source of resistance for potato breeding. No significant interactions were found between bacterial strains and potato and S. commersonii genotypes, and differences in aggressiveness among R. solanacearum strains were consistent with previously identified groups based on tomato and potato inoculations. Moreover, variation in responses to R. solanacearum was observed among the S. commersonii accessions tested.

scholarly journals Bacterial Wilt Resistance in Tomato, Pepper, and Eggplant: Genetic Resources Respond to Diverse Strains in the Ralstonia solanacearum Species Complex

2011 ◽  
Vol 101 (1) ◽  
pp. 154-165 ◽  
Author(s):  
A. Lebeau ◽  
M.-C. Daunay ◽  
A. Frary ◽  
A. Palloix ◽  
J.-F. Wang ◽  
...  
Keyword(s):  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Species Complex ◽  
Effective Control ◽  
Economic Losses ◽  
Wilt Resistance ◽  
The Core ◽  
Intermediate Phenotypes ◽  
Vascular Elements ◽  
Pathogen Strains

Bacterial wilt, caused by strains belonging to the Ralstonia solanacearum species complex, inflicts severe economic losses in many crops worldwide. Host resistance remains the most effective control strategy against this disease. However, wilt resistance is often overcome due to the considerable variation among pathogen strains. To help breeders circumvent this problem, we assembled a worldwide collection of 30 accessions of tomato, eggplant and pepper (Core-TEP), most of which are commonly used as sources of resistance to R. solanacearum or for mapping quantitative trait loci. The Core-TEP lines were challenged with a core collection of 12 pathogen strains (Core-Rs2) representing the phylogenetic diversity of R. solanacearum. We observed six interaction phenotypes, from highly susceptible to highly resistant. Intermediate phenotypes resulted from the plants' ability to tolerate latent infections (i.e., bacterial colonization of vascular elements with limited or no wilting). The Core-Rs2 strains partitioned into three pathotypes on pepper accessions, five on tomato, and six on eggplant. A “pathoprofile” concept was developed to characterize the strain clusters, which displayed six virulence patterns on the whole set of Core-TEP host accessions. Neither pathotypes nor pathoprofiles were phylotype specific. Pathoprofiles with high aggressiveness were mainly found in strains from phylotypes I, IIB, and III. One pathoprofile included a strain that overcame almost all resistance sources.

scholarly journals Evaluation of Resistance Sources of Tomato (Solanum lycopersicum L.) to Phylotype I Strains of Ralstonia solanacearum Species Complex in Benin

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1513
Author(s):  
Herbaud Zohoungbogbo ◽  
Adonis Quenum ◽  
Judith Honfoga ◽  
Jaw-Rong Chen ◽  
Enoch Achigan-Dako ◽  
...  
Keyword(s):  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Species Complex ◽  
Block Design ◽  
Agricultural System ◽  
Sources Of Resistance ◽  
Breeding Programs ◽  
Solanum Lycopersicum L ◽  
The University ◽  
Phylotype I

Finding sources of resistance to bacterial wilt (BW) caused by Ralstonia solanacearum species complex is a crucial step toward the development of improved bacterial wilt-resistant tomato varieties. Here, we evaluated new sources of bacterial wilt-tolerant/resistant tomato lines and identified associated phylotype/sequevar of R. solanacearum strains in Benin. Eighteen F5 lines and five checks were evaluated in two hotspots: the experimental site of the World Vegetable Center, Cotonou Benin, and the Laboratory of Genetics, Biotechnology and Seed Science of the University of Abomey-Calavi. Experiments were laid out in a randomized complete block design with four replicates. Data were collected on bacterial wilt incidence, horticultural and fruit traits and yield components. Across the two experiments, the F5 lines showed no wilting, while the local variety ‘Tounvi’ used as susceptible check showed 57.64% wilting. The wilting was due to BW and was associated with sequevars I-14, I-18 and I-31 of phylotype I. AVTO1803, AVTO1955-6 and H7996 were the highest yielding lines with 20.29 t·ha−1, 17.66 t·ha−1 and 17.07 t/ha, respectively. The sources of resistance to BW can be recommended to national agricultural system for dissemination or used in tomato breeding programs.

scholarly journals Comparison of Bacterial Communities in Soil Samples with and without Tomato Bacterial Wilt Caused by Ralstonia solanacearum Species Complex

2020 ◽  
Author(s):  
Ying Zhang ◽  
Anna Hu ◽  
Jianuan Zhou ◽  
Wenfei Zhang ◽  
Peng Li
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Diversity Index ◽  
Chemical Properties ◽  
Interaction Network ◽  
Wilt Disease ◽  
Community Diversity ◽  
Bacterial Strains

Abstract BackgroundRalstonia solanacearum is one of the most notorious soil-born phytopathogen that causes a severe wilt disease with deadly effects on many economically important crops. The microbial community structure and interactions are commonly changed between bacterial wilt susceptible soil and healthy soil. Here, the bacterial community structure, correlation analysis with soil chemical properties, interaction network of healthy soil (HS, nearly no disease happened at recent three years) and diseased soil (DS, suffered heavy bacterial wilt disease) were analyzed.ResultsCompared to DS, a higher bacterial community diversity index was found in HS, and the relative abundance of main genera Bacillus, Gaiellales, Roseiflexus, Gemmatimonadaceae, Nocardioides and Anaerolineacear reached significant level. Redundancy analysis on genus level indicated that rapid available phosphate played key role on bacterial community distribution difference, and showed negative correlation with the other four chemical properties. Interaction network analysis further demonstrated that the higher genus community diversity and more extensive interactions were existed in HS network and formed stable network, and the genera Mycobacterium, Cyanobacteria and Rhodobiaceae should be the key components that sustain the network stably. Seven clusters of orthologous groups reached significant level difference between HS and DS. Moreover, 55 bacterial strains with distinct antagonistic activities to R. solancearum were isolated and identified. ConclusionsIn summary, our findings indicate that the bacterial diversity and interaction network changed between the HS and DS samples, which are also provide a good research basis for future biological control to the bacterial wilt.

scholarly journals Low Temperature Induces Infectious Nonresuscitatable VBNC Cells in Ralstonia Pseudosolanacearum

2021 ◽  
Author(s):  
Neha Faridi ◽  
Merwyn Packia raj Samuel ◽  
Shalini Bhatt ◽  
Ankur Agrawal ◽  
Veena Pande ◽  
...  
Keyword(s):  
Low Temperature ◽  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Species Complex ◽  
Economic Importance ◽  
Bacterial Genus ◽  
Window Period ◽  
Ralstonia Pseudosolanacearum ◽  
Uv C

Abstract Ralstonia pseudosolanacearum and other members of Ralstonia solanacearum species complex (RSSC) causes the disease bacterial wilt in many crops of economic importance. The organism is known to form Viable But Non Culturable cells (VBNC). VBNCs resuscitate invitro during the “resuscitation window” period and are infectious Previous studies have identified nonresuscitatable VBNCs in various bacterial genus including RSSC, however their infectivity was not elucidated and described. In this work, VBNCs of two Ralstonia pseudosolanacearum strains were generated by exposing the microcosms to psychrophilic stress, UV-C radiation and 70% isopropanol. Both resuscitatable and nonresuscitatable VBNCs were observed in psychrophilic and UV-C stressed microcosms. The nonresuscitatable VBNCs generated at psychrophilic temperature were found infective. Based on resuscitation properties, nonresuscitatable VBNCs can be considered as a different VBNC type from resuscitatable VBNCs.

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